The effects of five moisture content on the longevity of mechanically shelled peanut seeds treated and not treated with fungicide were studied. The seeds were placed in hermetically sealed glass jars and stored in an unconditioned room in Campinas, State of São Paulo for a period of up to 22 months. The rate of deterioration was measured by the standard germination test. The 8.0 and 9.1% moisture content were extremely damaging to the longevity of the seeds including to those treated with fungicide. Seeds with the original moisture (7.0%) and treated with fungicide maintained reasonably well the germinability until nine months storage when they provided a percent germination around 60%. Seeds with 4.5 and 6.0% moisture content stored longer than those with higher moisture contents. At 14, 18, and 22 months storage seeds with 4.5% moisture content produced germination percentage significantly greater than those with 6.0%. The percent germination of fungicide-treated seeds was always statistically higher than non-treated seeds.